as I have a vw golf mk3 for day car, I would pick the golf gti fwd turbo.
There are plenty of euro tuners that got good results from the engine. some reported 300kw at fly with metal gasket stock bottom end. (pfff that all? )
This will get you started..
http://www.goapr.com.au/
Althought Astra turbo is relatively new in australia, shouldn't take people very long to start tuning them to get some good power too.
Oh yeah don't forget to check the insurance, very expensive even for N/A euro cars.